AQUEOUS 1-METHYLCYCLOPROPENE (1-MCP) TO DELAY RIPENING OF KEITT MANGO FRUIT WITH QUARANTINE HOT WATER TREATMENT

Abstract

Gaseous 1-methylcyclopropene (1-MCP) delays fruit ripening in some mango (Mangifera indica L.) varieties, but it requires 12 h of application in sealed containers. A recently developed aqueous formulation has demonstrated the same effectiveness as gaseous 1-MCP when applied as a postharvest dip for 1 to 5 min, allowing more flexibility for its application. The objectives of this research were to determine the effectiveness of aqueous 1-MCP on delaying the ripening process, extension of shelf life, and quality maintenance of Keitt mango fruits, as well as to prove whether the quality is affected by the Quarantine Hot Water Treatment (QHWT). Three experiments were conducted, two of them during 2013 in Nayarit, Mexico and Florida, USA and another one during 2014 in Nayarit, Mexico. Aqueous 1-MCP caused some delay of fruit ripening as shown by improved maintenance of fruit firmness, but it had a negative interaction with QHWT causing fruit spots and lenticel darkening. This negative effect was lower when 1-MCP was applied before or after QHWT without hydrocooling, and higher when applied after QHWT + hydrocooling. In contrast, aqueous 1-MCP applied to fruits without QHWT maintained 92 % of the initial firmness at the end of the 21-day period of refrigerated shipping simulation and delayed the ripening process for 4 d during marketing simulation without affecting external appearance. Thus, aqueous 1-MCP may represent a viable alternative for markets that do not require mandatory QHWT.